tentukan nilai fungsi f(x) jika diketahui f¹(x) = 4x-1 dan f (3) = 20

f'(x) = 4x - 1
f(x) = 2x² - x + c
f(3) = 20
2(3)² - 3 + c = 20
18 - 3 + c = 20
15 + c = 20
c = 20 - 15 = 5
f(x) = 2x² - x + 5